Stepladder, trestle, and the like



Dec. 18, 1945. ALLAN STEP LADDER, TRESTLE, AND THE LIKE Filed June 22, 1944 2 Sheets-Sheet 1 Ira- Dec. 18, 1945. I J, ALLAN 'STEP LADDER, TRESTLE, AND THE LIKE Filed June 22, 1944 2 Sheets-Sheet 2 steps or rungs and Patented Dec. 18, 1945 L "UNITED STATES PATENT OFFICE s'rnrnannnnp'rifsistigz, ANnLina r I 7 Application June 22, 1944,,Serial No. 541,588- V InAustralia-August28,1943 x aromas-29) 1 11 claims.

This invention relates to improvements in step I ladders and the likethjat' is to say, ladders of thetype having a forward portion provided with a'rearward portion which constitutes a prop and which is hingedly connected 'atlts upper end to the upper partof the front or steppedportion. I V 1 More particularly the aforesaidprop' usually comprises, a spaced pair of legs rigidly connected [I togethen'th spa ing of such legs beingapproximately the same as the Spacingoi the legs or side members'o'f the front orfstep'ped portion offthe ladder.

Thus in use the step ladder is supportedlat four mutually spaced pointsv and, in order that it may be safe and stable in use, it is necessary to arrange these four points or legs substantially in the same horizontal plane. Accordingly, when such a' ladder'is mounted on an' unevensurface, it isjgenerally necessary to place a wedge orj equiva-lent packing' below'one or more of the legs.

Now, "the general object of this invention is' to provide improvements; in step ladders and the like while a more specificobject is to provide" a step ladder or simple and "efiectiveconstruction which will overcome 'or minimise the abovemen- .tioned disadvantages of step ladders'at'present in use. Yet another object is to provide astep ladder'havingan adjustable 'prop'capable or being I locatedclose to a reentrant corner.

Accordingly th invention broadly resides in-a step ladder, trestle or the likehavingarront portion and a supporting prop, said prop comprising a longitudinally disposed-member, means pivot= 7 ally connecting the upper end of the longitudi nally disposed member to an upper partfof the front portion, a cros'smember pivotedintermediate ltsends to the longitudinally disposed memher, a pair or prop legs arranged one at each side of thelongitudinally disposedmember' and pivotally connected tosaid rigidmember; link means spaced from said cross member, and pivotally connected to the prop legs, and means for main taining said longitudinally disposed member in a plane substantially parallel tothe'plane of the prop legs.

Thesaid link-means is referably soifornied' or arranged as to provide a guide slot for the adlae cent portion of th longitudinally extending member. Preferably the longitudinally extending member and an intermediate part of said link means are adapted to be pivotally connected together when required.-

, The said link means preferably comprises a pair of transverse links arranged respectivel'y'at the front and back of the prop legs each such link being capable of being so arranged that it extends between and 'adjustably connects a corresponding prop leg to the central longitudinal member in orderthat the lower ends of the prop legs may be adjusted towards and from each other. For this purpose the'central longitudinal member may be provided with a longitudinally extendingslot or'with a series of adjustment holes to receive apivot bolt for the inner ends of the 'said'links.

Other features or-the invention are hereinafter described; i

In the drawings, which illustrate an exemplary form of theinventionz' Figure 1 is a view in perspective of a step ladder in accordance with the invention.

Figure 2 is a viewin vertical section or the upper portion of the ladder shown in Figure l. Figure 3'is a view in sectional planof the prop and'is taken on'the plane indicated by the line 3-3 of Figure 1. V a

Figures 41 and ,5' are views in rearelevation of the ladder and illustrate the prop members under different conditions of use; Figure 6 is aviewtoa larger scale and shows the propv arranged in an alternative manner;

Figill'e'lis a View in perspective showing a still further arrangementof the prop legs; and

Figures Sandi? are views in elevation and sectional side elevation respectively showing a modification of .the invention.

' The stepladder'shown in the drawings has a front portion which is constructed in substantially the usual way-that'is to say, it comprises a spacedpair of side members [0 supporting the ends of aplurality of transversely disposed steps ll. 'A transversely disposed board l2, hereinafter termed the backboard, of the kind commonly provided on step. ladders, is secured rigidly to the rearfaces. of'the upper ends of the side members and. serves for the attachment of a hinged prop. The prop includes a longitudinally disposed strut l3 secured at its upper end to a laterally prop 1egs|1 are'pivotally connected to the opposite ends of this lever I6. These prop legs may normally diverge downwardly to some extent as shown in Figures 1 and 4.

The prop legs are also connected to each other some distance below the lever I6 by a spaced pair of transversely disposed links I8 and I9 which are arranged respectively at the backand front of the prop legs as shown in Figures 1 and 3 and are connected thereto by common detach-.

able bolts 20 provided with wing nuts. Thus a lateral guide slot is formed by and between the spaced links, and the lower part of the strut I3 extends therethrough and normally is pivotally connected to the central parts thereof by a common removable bolt 2I.

From the foregoing description it will be apparent that normally the prop legs. I6 are capable of free longitudinal movementsin opposite directions relatively to the strut- I3." If, therefore, the front or stepped portion of the ladder is placed on a comparatively level surface and the prop legs placed on a comparatively uneven quite stable when pivotal'movements of the prop I legs are not restricted. 'By removing the aforesaid bolt 2I which-nonmally connects" the lower portion of the strut to the center of the pair of transverse links I8 and I9, the'lower end of the strut is capable of-swinging in the guideslot formed by and between these links. Thus, as shown inFigure 5, if the front stepped portion of the ladder is supported on an uneven surface so that the steps thereof incline to one side, the prop legs may be arranged to provide a stable support therefor;

Injthis connection it is to be noted that'the links l8 and I9 maintain the strut 13 at all times in the common plane'of the prop legs;

If desired, means may be provided for retaining the strut in its adjusted position when the ladder is arranged as shown in Figure Thus, as shown by way of example in'Figures 8 and 9, the lower end of the strut I3 may be fittedwith a bracket 24 in which an adjustable clamping screw '25 is mounted.

The lower end of the prop may be prevented from spreading relatively to the front stepped portion of the ladder by any suitable means such as cords or other tie members which are commonly used for this purpose, and such member may be connected either to the lower end of the strut or to corresponding portions of the prop legs.

When the ladder is comparatively small, however, it is preferred to limit the angular movements of the strut by arranging the upper end of the board M to abut against the adjacent end of the back board I2 as shown in Figure 2. There are many occasions when it is desirable to arrange the prop of a step ladder asclose as possible to a reentrant corner such as the corher of a room, and for this reason the strut I3 is provided with a longitudinal slot 22 whereby the links I8 and I9 may be arranged in the alangle to the bolt 2I.

ternative manner shown in Figure 6 in which each link extends from one of the prop legs to the bolt 2| which latter for this purpose, is mounted in the slot 22. Thus, as shown in full lines in Figure 6, the lower ends of the prop legs may be arranged close ogether for the purpose referred to, while, should it be necessary under special conditions to increase the normal spacing of the prop legs, this may be accomplished by moving the bolt2I downwardly in the slot 22 and by tightening same in the desired position of adjustment (see broken lines in Figure 6).

It will be noted that the lower end of the slot 22 is disposed well above the level of the bolts 20 in the prop legs, whereby the links I8 and I9 always incline upwards at a substantial Thus the bolt 2I (when tightened) can be moved freely upwards in the slot 22 merely by displacing the lower ends of the prop legs towards each other. v

' If'desired, the 'sl0tf2'2 may be replaced by a series of adjustment holes- Again, when the ladder'is arranged close to awall with the steps atright angles thereto, as shown in Figure '7, the links I8 and I9 may be arranged as shown in the figure whereby the inner prop leg is disposed substantially parallel to the strutwhile the outer prop leg diverges outwardly and downwardly therefrom-at a substantial angle to provide increased lateral stability.

It will be evident that theinvention is applicableto trestles and the like as well as tostep ladders.

I claim:

l. A step ladder or the like having a front stepped portion and a supporting prop, said prop comprising a longitudinally disposed member, means pivotally connecting th upper end of the 40 longitudinally disposed member to an upper part of the front portion, a cross member pivoted intermediateits ends to the longitudinally. disposed member, a pair of prop legs arranged one at each side ofthe longitudinally disposed member and pivotally connected to said cross memher, and linkmeans spacedfrom said cross memher and pivotally connected to the prop legs in such a manner asto form a transverse guide for the adjacent part of said longitudinally dis-- posed memberwhi'ch is capable of relative lateral movements.)

2. A step ladder or the like having a front steppedportion and a supporting prop, said prop comprising a longitudinally disposed member pivotally connected at its upper end to the front portion, a cross member pivotally connected intermediate its ends to an upper part of said longitudinal member, alpair of prop legsarranged one at each side of said longitudinal member, means. pivotally connecting each prop leg to a corresponding part of said cross member, laterally extending link means arranged-belowsaid cross member, and means pivotally connectin said link means to said pro less, said link means providing a transverse guide slot for the adjacent part of said longitudinal member.

3. A step ladder or the like having a front stepped portion andja supporting prop, said prop comprising a longitudinally disposed member hingedly connected at its upper end to the front portion, a cross member pivotally connected intermediate its ends to an upper part of the, lonitudinal member, a pair of prop legs arranged one at each side of said longitudinally. disposed memb r. eans.,p o 11y c n ec n an upper tions of said links to the respective prop legs, at

part of each prop leg to a corresponding part of least one endot one link being detachable from said cross member, laterally extending link means arranged below said cross member and means rpivotally'connecting spaced portions of said link means to'said prop legs, said link means form- 'ing'a transverse guide for the adjacent part of longitudinally disposed member, and means 'adaptedt-o pivotally connect said longitudinally disposed member to said link means intermediate said'xprop legs while. guided by the same, whenever. desired.

41A.- step ladder or the like having a. front -steppe'd portion and-a supporting prop, said prop comprising --a longitudinally disposed member hingedly connected adjacent its upper en to an upper part of said front portion, a cross member pivoted intermediate its ends to the longitudinally disposed member, a pair of prop legs arranged one at each side of the longitudinally disposed member, and pivotally connected to said cross member, link means spaced from said cross member and pivotally connected to the prop legs, in such a manner as to form a transverse guide for said longitudinally disposed member, and means for optionally connecting said longitudinally disposed member to said link means at variousaltemative positions while guided by said link means.

5. A step ladder having a front stepped portion and asupporting prop, said prop comprising a longitudinally disposed member, means pivotally connecting an upper part of the longitudinally disposed member to an upper part of the front stepped portion of the ladder, a cross lever pivotally connected intermediate its ends to said longitudinally disposed member, a pair of prop legs arranged one at each side of said longitudinally disposed member and pivotally connected to said cross lever, and a pair of rigid links spaced from said lever and extending between and pivotally connecting the prop legs, said links being arranged respectively at the front and back of the longitudinally disposed member and forming guides therefor.

6. A step ladder having a front stepped portion and a supporting prop, said prop comprising a longitudinally disposed member, means pivotally connecting an upper part of the longitudinally disposed member to an upper part of the front stepped portion of the ladder, a cross lever'pivotally connected intermediate its ends to an upper part of said longitudinally disposed member, a pair of prop legs arranged one at each side of said longitudinally disposed member and pivotally connected to said cross lever, and an opposed pair of transverse links arranged below the cross lever and extending between the prop legs, and common pivot members connecting the adjacent pairs of ends of the transverse links to the corresponding prop leg, said links being respectively arranged at the back and front of the longitudinally disposed member and forming guides therefor.

respectivelyat the front and back of the longitudinally disposed member and forming a, guide therefor.

8. A step ladder or the like having a front stepped portion and a prop, said prop comprising a longitudinally disposed member provided with an apertured portion, a cross member pivoted to said longitudinally disposed member and extending from both sides thereof, a pair of prop legs arranged one at each side of the longitudinally disposed member and pivotally connected to corresponding portions of the cross member, and a pair of rigid links, one of said links having one of its ends pivotally connected to one of said prop legs at a point spaced from the said cross member, one end of the other link being similarly pivoted to the other prop leg and each of said link being additionally capable of alternative connection either to the opposite prop leg or to the said apertured portion of said longitudinally disposed member.

9. A step ladder or the like having a front stepped portion and a prop, said prop comprising a longitudinally disposed mem ber provided with an aperture and pivotally connected adja cent its upper end to the adjacent part of said front portion, a cross lever pivotally connected intermediate its ends to said longitudinally disposed member, a pair of prop legs arranged one at each side of the longitudinally disposed member, each leg being pivotally connected to the corresponding end of said cross lever and a pair of links spaced from said lever, one end of one of said links being pivotally connected to one of said prop legs, the other link having one of its ends pivotally connected to the other prop leg and the remaining end of each link being capable of alternative connection either to the opposite prop leg or to the said longitudinally disposed member :by means of said aperture in the latter, said links, when arranged to extend between and connect the pair of prop legs, being arranged respectively at the front and back of the longitudinally disposed member and forming a guide therefor.

10. A step ladder or the like having a stepped front portion and a prop, said prop comprising a longitudinally disposed member having a slotted portion and pivotally connected adjacent its upper end to the adjacent part of said front portion, a cross lever pivotally connected intermediate its ends to said longitudinally disposed member, a pair of prop legs arranged one at each side of the longitudinally disposed member, each leg being pivotally connected to the corresponding end of said cross lever and a pair of links spaced from said lever, one end of one of said links being pivotally connected to one of said prop legs, the other link having one of its ends pivotally connected to the other prop leg and the remaining end of each link being capable of alternative connection either to the opposite prop leg or to the said slotted portion of longitudinally disposed member, said links, when arranged to extend between and connect the pair of prop legs, being arranged respectively at the front and back of the longitudinally disposed member and forming a guide therefor,

and means adapted to connect said longitudinally disposed member and at least one of said links pivotally together. intermediate said prop legs when said links extend between and are pivotally connected at their opposite ends to the prop legs.

11. A step ladder or the. like having a front stepped portion and'a prop, said prop comprising a longitudinally disposed memberprovided with a longitudinally slotted portion and pivotally connected adjacent its upper end to the adjacent part of said front portion, a cross lever pivotally connected intermediate its ends to said longitudinally disposed member, a pair of prop legs arranged one at each side of the longitudinally disposed member, each leg being pivotally connected to thecorresponding endv of said cross lever, a pair of links spaced from said lever, one end of one of said links being pivotally connected to one of said prop legs, the other link having one of its ends pivotally connected to the other prop leg, and connecting means at the remaining end of each link adapted to connect the same alternatively either to the opposite prop leg or to said longitudinally slotted portion of said 1ongitudinally disposed member, said links, when arranged to extend between and connect said pair of prop legs, being arranged respectively at the front and back of the longitudinally disposed member and forming a guide therefor.

' JOHN ALLAN. 

